I've claimed 198 QSOs for my most serious SS effort since 2001. As the lines in the log filled, my attention increasingly went to the checks. So many from the 50s through the 70s and almost none from the present decade. My soapbox for the event simply says I'd plot the curve.
I don't have a plotting program and can't bother right now with trying to figure out if OO Calc will let me draw a bell curve, but a couple of key statistics are these:
Number of Years Since First Licensed
mean ±SD = 40.38 ±12.58
Just a single check from the 21st century. That's about one-half of one percent.
On the other end of the spectrum, it was very nice to work W4KFC, licensed 75 years in 2008 and 5-time CW Sweepstakes winner.